ifconfig (Interface Configuration)
The ifconfig command is a system administration utility in Unix-like operating systems to configure, control, and query TCP/IP network interface parameters. It is the primary tool for checking your local IP address and network hardware status.
1. Basic Usage
ifconfig [interface] [options]
2. Key Information in Output
| Label | Description |
|---|---|
| inet | The IPv4 address assigned to the interface. |
| netmask | The subnet mask used to define the network boundaries. |
| ether | The MAC address (Physical address) of the hardware. |
| UP/RUNNING | Indicates that the network interface is active and functioning. |
3. Practical Examples
① Displaying all active interfaces
ifconfig
② Viewing a specific interface (e.g., wlan0 for Wi-Fi)
ifconfig wlan0
③ Enabling or Disabling an interface
sudo ifconfig eth0 up
sudo ifconfig eth0 down
4. [Tip] ifconfig vs ip addr
While ifconfig is a classic tool, it is being deprecated in favor of the more powerful ip command from the iproute2 package. If ifconfig is not found, try:
ip addr show